Dump truck



Jan. 10, 1950 A. CRESCI 2,494,377

DUMP TRUCK 2 Sheets-Sheet 1 Filed Dec. 11, 1945 A. L CRESCI wfim Aux; 714 may Jan. 10, 1950 A. L. cREscl I 2,494,377

I DUMP TRUCK Filed Dec. 11, 1945 2 Sheets-Sheet 2 :EZLEE Qwue/wtom 'AQL. CRESCI Was Patented Jan. 10, 1950 iJNITED STATES PATENT OFFICE DUMP TRUCK Anthony L. Cresci, vineland, N. J. Application December 11, 1945, Serial No. 634,320

2 Claims. (01. 298- 1 The present invention relates to dump trucks, particularly to mechanism for hoisting the truck body.

It is desirable for some purposes, such as the delivery of coal and loads of a similar character, that the truck body be elevated to a relatively great height and at the same time that the body be tilted to such an angle that the load will be readily discharged by gravity. This invention provides for such high-lift and includes, in addition tothe. usual pivoted crossed levers and hydraulic hoist mechanism, auxiliary hoisting apparatus designed to elevate and tilt the body to effect a higher lift and greater dumping angle of the truck body.

J Itiisone of the objects of the invention to provide additional lift cylinders connected to the fluid supply of the main hoisting mechanism and acting on the front end of the body further to elevate and tilt the body.

It is another object of the invention to provide an arrangement of fluid supply lines and valves therefor to control the auxiliary as Well as the main hoisting mechanism.

Other objects will be apparent from the following description of the invention taken in connection with the accompanying drawings, in which Fig. 1 is a side elevation of a preferred embodiment of the invention, certain of the parts being broken away better to illustrate the controls;

Fig. 2 is a front elevation of the body showing the positions of the auxiliary lift cylinders, part of the underframe being broken away to illustrate the manner in which the cylinders are pivoted to the body and to the underframe;

Fig. 3 is a fragmentary diagrammatic plan of the hydraulic system and the valves for controlling its operation.

In the drawings, the vehicle chassis or main frame I supports, by means of pivoted crossed levers II and 12, the sub-frame l3 on which body I4 is pivotally mounted as by pins l5 adjacent the rear end of the sub-frame. Toggle links [6 and I! connect lever H to the chassis, link I6 being pivoted on the chassis and link I! being pivotally connected to the lower end of lever H, the upper end of which is pivoted to sub-frame [3 at l8. Link 19 connects the upper end of lever l2 to the sub-frame, the lower end of lever l2 being pivoted on the chassis. each other by a pivot rod 20.

The hydraulic hoisting mechanism which eifects simultaneous elevation and tilting of the sub-frame, comprises cylinder 2|, pivoted on chassis ID at 22, and the ram or piston 23, pivot- Levers H and I2 are connected to ally connected to the pivot rod 20. Asource of fluid under pressure, which may be oil or some.

other suitable fluid, includes a tank 24 and. pump 2'5, theoil .or other fluidbeing pumped from tank 24 to cylinder 2! by pump25 to. elevate the crossed levers and the body connected thereto. The pump is driven from the vehicle motor through a clutch 2-6 and shaft 21, suitable universal joints 28 being interposed between the clutch and the pump.

Adjacent each corner at the front of the subframe .and independent of the main hoisting mechanism is an: auxiliary cylinder 29 and a piston. 3%; Since these cylinders, pistons and theirmountings are similar, only one of them will be described. Attached to each of cylinders 291s a .ring 3| having diametrically opposite recesses e240 accommodate pinsSB, the latter also passing through openings 34 in the sub-frame so that the cylinder is swingably mounted on the sub-frame. A pair of recessed fulcrum blocks 35 are welded or otherwise secured to longitudinal frame member 36 of the body, and to bracket 3! fastened to frame member 36, pin 38 passing through these blocks and through a recess 39 in the upper end of piston 30. It will thus be seen that piston 30 is mounted for swinging movement with respect to bOdy l4.

The means for controlling the supply of fluid under pressure and the return of the fluid to the supply tank are shown in Figs. 1 and 3. Assuming the body is to be lifted, the valve Ml between tank 24 and the discharge side of pump 25 is first closed. Fluid under pressure then flows through connection ll to cylinder 2!, forcing piston 23 in a direction to elevate the body. At this time valve 42 may be open or closed, depending on whether it is desirable to employ the auxiliary hoist before or after complete elevation of the main hoist. When valve 42 is open, it will be seen that fluid under pressure will also be supplied to cylinders 29 through flexible connections i3, 44, in which case the body will be tilted about pins 55 further to increase the dump angle of the body. Check valve 45 is interposed between the discharge side of pump 25 and the hoist cylinders to maintain pressure in the lines after the pump has been stopped, the body being thus held at the desired height whether it be complete or only partial elevation.

To lower the body, the pump is disconnected from the motor by throwing out clutch 26, and valves 46, 42 opened. The weight of the body is sufiicient to force the motive fluid out of the cylinders and return it to storage tank 24. Since the pressure exerted by piston 23 will be greater than that in cylinders 29 during the lowering of the body, the crossed levers will first return to their lowermost positions, whereupon the weight of the body will force fluid from the auxiliary cylinders. The body and sub-frame will then rest on the chassis in parallel relation thereto.

From the foregoing description it will be apparent that it is possible to elevate a, dump truck body to a relatively great height and at this height to tilt the body to a greater dump angle than that resulting from the elevation by the main hoisting mechanism. Since there are limitations to the angle to which the body may be tilted by the conventional combined hoisting and tiltingmechanisms, it is obvious that the auxiliary tilting device provides means to facilitate and accelerate the unloading of the body.

While a preferred embodiment of the'invention has been illustrated and described, it is to be understood that it is susceptible of modification and is not to be limited to the exact arrangement of parts shown in the drawings.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In combination, a dump truck including a main frame, a sub-frame and a body, said subframe being movably supported on said main frame and said body being pivotally mounted on said sub-frame adjacent the rear end of the subframe, a source of fluid under pressure, means operated by fluid under pressure from said source for simultaneously elevating and tilting said subframe with the front end of the sub-frame at a greater height than that of the rear end of the sub-frame, a cylinder pivoted to said sub-frame, a piston in said cylinder and pivoted to said body, and means for supplying fluid under pressure 4 from said source to said cylinder for raising only the front end of said body with respect to said sub-frame.

2. In combination, a dump truck including a main frame, a sub-frame and a body, a pair of crossed levers, each of said levers having a pivotal connection at one end with said main frame and a pivotal connection at its other end with said body, a source of fluid under pressure, a cylinder connected at one end to said main frame, a piston in said cylinder and pivoted to said crossed levers, means for supplying fluid under pressure from said source to said cylinder for simultaneously elevating said levers and tilting said sub-frame in one direction, a pivotal connection between said sub-frame and said body,

- an auxiliary cylinder pivoted to said sub-frame,

a piston in said auxiliary cylinder and pivoted to said body, and means for supplying fluid under pressure from said source to said auxiliary cylinder for tilting said body in said one direction with respect to said sub-frame.

ANTHONY L. CRESCI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,650,815 Barrett Nov. 29, 1927 FOREIGN PATENTS Number Country Date 231,745 Great Britain Apr, 9, 1925 696,609 France Oct. 14, 1930 

